“We hope to be a service that everyone uses to inspire their future, whether that's dinner tomorrow night, a vacation next summer, or a dream house someday." said Pinterest CEO Ben Silbermann. "This new investment enables us to pursue that goal even more aggressively."

To put the valuation in context, Pinterest is now worth almost four times the sum that both Tumblr and Instagram sold for, $1.1 and $1 billion dollars respectively. The three sites primarily compete over photo and image sharing, and the money seems to be a bet by investors that Pinterest has solidified its stake in that arena.

The investment also means that Pinterest is unlikely to go public anytime soon. It will likely be at least a year until the site makes that move, if it so chooses. The money infused by the investors was likely viewed as by the company as a favorable alternative to an IPO at the moment. This could be the result of a number of factors, but one might be that the company simply did not have the metrics to impress Wall Street and still believes it's can grow rapidly in the near future. It has also barely waded into revenue generating activities such as advertising.